Researchers at Purdue University are working on tech that will turn every cellphone into a roaming nuclear weapon sniffer and are lobbying Congress to legally require cellphone users and carriers to participate. The Distributed Nuclear Detection by Ubiquitous Cellphone project would be kind of like the massive cellphone dragnet in The Dark Knight, but it would look for terrorists sneaking dirty bombs and nuclear weapons instead of the Joker. Like the Batman system, the more phones on the ground, the better, since it would be able to triangulate the source of radiation more accurately. Phones closest to the deadly stuff as they pass by would give off stronger signals, pinpointing where it's at, or how it's moving in real time. Also, the larger the scale of the project, the less the system would cost per phone—right now it's around $50-$100 a phone. Blown up to a hundred million phones, the price would plummet. Obviously, there are some major civil rights issues here, especially if you're legally required to be a constantly lo-jacked, walking bomb detector for the Man. Newsweek suggests a more diplomatic and less creepy solution, where government agencies would pay you to opt-in. I think that's one paycheck I'd have to pass on. [Newsweek]